Expression of xylanase enzymes from thermophilic microorganisms in fungal hosts (original) (raw)

Aims: To express a gene encoding a heterologous fungal xylanase in Trichoderma reesei. Methods and Results: Humicola grisea xylanase 2 (xyn2) cDNA was expressed in Trichoderma reesei under the main cellobiohydrolase I (cbh1) promoter (i) as a fusion to the cellobiohydrolase I (CBHI) secretion signal and (ii) the mature CBHI core-linker. The recombinant xylanase (HXYN2) was secreted into the cultivation medium and processed in a similar fashion to the endogenous T. reesei xylanases, resulting in an active enzyme. Conclusions, Signi®cance and Impact of the Study: HXYN2 was successfully processed in T. reesei. Composition of the culture medium affected the HXYN2 yields, favouring Avicellactose as a carbon source. Best yields (about 0á5 g l )1 ) in shake¯ask cultivations were obtained from a transformant where xyn2 was fused directly to the CBHI secretion signal.